/*
 *	I2O block device driver. 
 *
 *	(C) Copyright 1999   Red Hat Software
 *	
 *	Written by Alan Cox, Building Number Three Ltd
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 * 	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	This is a beta test release. Most of the good code was taken
 *	from the nbd driver by Pavel Machek, who in turn took some of it
 *	from loop.c. Isn't free software great for reusability 8)
 *
 *	Fixes:
 *		Steve Ralston:	Multiple device handling error fixes,
 *				Added a queue depth.
 *		Alan Cox:	FC920 has an rmw bug. Dont or in the
 *				end marker.
 *				Removed queue walk, fixed for 64bitness.
 *		Boji T Kannanthanam:
 *				Support for dynamic device creation/deletion
 *	To do:
 *		Multiple majors
 *		Serial number scanning to find duplicates for FC multipathing
 *		Set the new max_sectors according to max message size
 *		Use scatter gather chains for bigger I/O sizes
 */

#include <linux/major.h>

#include <linux/module.h>

#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/ioctl.h>
#include <linux/i2o.h>
#include <linux/blkdev.h>
#include <linux/malloc.h>
#include <linux/hdreg.h>

#include <linux/notifier.h>
#include <linux/reboot.h>

#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <linux/smp_lock.h>
#include <linux/wait.h>


#define MAJOR_NR I2O_MAJOR

#include <linux/blk.h>

#define MAX_I2OB	16

#define MAX_I2OB_DEPTH	128		  
#define MAX_I2OB_RETRIES 4


/*
 * Events that this OSM is interested in
 */
#define I2OB_EVENT_MASK    (I2O_EVT_IND_BSA_VOLUME_LOAD |   \
			    I2O_EVT_IND_BSA_VOLUME_UNLOAD | \
			    I2O_EVT_IND_BSA_VOLUME_UNLOAD_REQ | \
			    I2O_EVT_IND_BSA_CAPACITY_CHANGE)


/*
 * I2O Block Error Codes - should be in a header file really...
 */
#define I2O_BSA_DSC_SUCCESS           0x0000
#define I2O_BSA_DSC_MEDIA_ERROR	      0x0001
#define I2O_BSA_DSC_ACCESS_ERROR      0x0002
#define I2O_BSA_DSC_DEVICE_FAILURE    0x0003
#define I2O_BSA_DSC_DEVICE_NOT_READY  0x0004
#define I2O_BSA_DSC_MEDIA_NOT_PRESENT 0x0005
#define I2O_BSA_DSC_MEDIA_LOCKED      0x0006
#define I2O_BSA_DSC_MEDIA_FAILURE     0x0007
#define I2O_BSA_DSC_PROTOCOL_FAILURE  0x0008
#define I2O_BSA_DSC_BUS_FAILURE	      0x0009
#define I2O_BSA_DSC_ACCESS_VIOLATION  0x000A
#define I2O_BSA_DSC_WRITE_PROTECTED   0x000B
#define I2O_BSA_DSC_DEVICE_RESET      0x000C
#define I2O_BSA_DSC_VOLUME_CHANGED    0x000D
#define I2O_BSA_DSC_TIMEOUT           0x000E


/*
 *	Some of these can be made smaller later
 */

static int i2ob_blksizes[MAX_I2OB<<4];
static int i2ob_hardsizes[MAX_I2OB<<4];
static int i2ob_sizes[MAX_I2OB<<4];
static int i2ob_media_change_flag[MAX_I2OB];
static u32 i2ob_max_sectors[MAX_I2OB<<4];

static int i2ob_context;

struct i2ob_device
{
	struct i2o_controller *controller;
	struct i2o_device *i2odev;
	int unit;
	int tid;
	int flags;
	int refcnt;
	struct request *head, *tail;
	int max_segments;
	int done_flag;
};

/*
 *	FIXME:
 *	We should cache align these to avoid ping-ponging lines on SMP
 *	boxes under heavy I/O load...
 */
 
struct i2ob_request
{
	struct i2ob_request *next;
	struct request *req;
	int num;
};


/*
 *	Each I2O disk is one of these.
 */

static struct i2ob_device i2ob_dev[MAX_I2OB<<4];
static int i2ob_devices = 0;
static int i2ob_dev_count = 0;
static struct hd_struct i2ob[MAX_I2OB<<4];
static struct gendisk i2ob_gendisk;	/* Declared later */

/*
 * Mutex and spin lock for event handling synchronization
 * evt_msg contains the last event.
 */
DECLARE_MUTEX(i2ob_evt_sem);
static spinlock_t i2ob_evt_lock = SPIN_LOCK_UNLOCKED;
static unsigned int evt_msg[MSG_FRAME_SIZE>>2];
DECLARE_WAIT_QUEUE_HEAD(i2ob_evt_wait);


static atomic_t queue_depth;		/* For flow control later on */
static struct i2ob_request i2ob_queue[MAX_I2OB_DEPTH+1];
static struct i2ob_request *i2ob_qhead;

static struct timer_list i2ob_timer;
static int i2ob_timer_started = 0;

#define DEBUG( s )
/* #define DEBUG( s ) printk( s ) 
 */

static int i2ob_install_device(struct i2o_controller *, struct i2o_device *, int);
static void i2ob_end_request(struct request *);
static void i2ob_request(void);
static int do_i2ob_revalidate(kdev_t, int);
static int i2ob_query_device(struct i2ob_device *, int, int, void*, int);
static int i2ob_evt(void *);

static int evt_pid = 0;
static int evt_running = 0;
static int scan_unit = 0;

static void i2ob_new_device(struct i2o_controller *, struct i2o_device *);
static void i2ob_del_device(struct i2o_controller *, struct i2o_device *);
static void i2ob_reboot_event(void);


/*
 * Dump messages.
 */
static void i2ob_dump_msg(struct i2ob_device *dev,u32 *msg,int size)
{
	 int cnt;

	 printk(KERN_INFO "\n\ni2o message:\n");
	 for (cnt = 0; cnt<size; cnt++)
	 {
		  printk(KERN_INFO "m[%d]=%x\n",cnt,msg[cnt]);
	 }
	 printk(KERN_INFO "\n");
}

/*
 *	Get a message
 */

static u32 i2ob_get(struct i2ob_device *dev)
{
	struct i2o_controller *c=dev->controller;
   	return I2O_POST_READ32(c);
}
 
/*
 *	Turn a Linux block request into an I2O block read/write.
 */

static int i2ob_send(u32 m, struct i2ob_device *dev, struct i2ob_request *ireq, u32 base, int unit)
{
	struct i2o_controller *c = dev->controller;
	int tid = dev->tid;
	unsigned long msg;
	unsigned long mptr;
	u64 offset;
	struct request *req = ireq->req;
	struct buffer_head *bh = req->bh;
	int count = req->nr_sectors<<9;

	/* Map the message to a virtual address */
	msg = c->mem_offset + m;
	
	/*
	  * Build the message based on the request.
	 */
	writel(i2ob_context|(unit<<8), msg+8);
	writel(ireq->num, msg+12);
	writel(req->nr_sectors << 9, msg+20);
	
	/* This can be optimised later - just want to be sure its right for
	   starters */
	offset = ((u64)(req->sector+base)) << 9;
	writel( offset & 0xFFFFFFFF, msg+24);
	writel(offset>>32, msg+28);
	mptr=msg+32;
	
	if(req->cmd == READ)
	{
		writel(I2O_CMD_BLOCK_READ<<24|HOST_TID<<12|tid, msg+4);
		/* We don't yet do cache/readahead and other magic */
		writel(1<<16, msg+16);
		while(bh!=NULL)
		{
			/*
			 *	Its best to do this in one not or it in
			 *	later. mptr is in PCI space so fast to write
			 *	sucky to read.
			 */
			if(bh->b_reqnext)
				writel(0x10000000|(bh->b_size), mptr);
			else
				writel(0xD0000000|(bh->b_size), mptr);
	
			writel(virt_to_bus(bh->b_data), mptr+4);
			mptr+=8;
			count -= bh->b_size;
			bh = bh->b_reqnext;
		}
	}
	else if(req->cmd == WRITE)
	{
		writel(I2O_CMD_BLOCK_WRITE<<24|HOST_TID<<12|tid, msg+4);
		writel(1<<16, msg+16);
		while(bh!=NULL)
		{
			if(bh->b_reqnext)
				writel(0x14000000|(bh->b_size), mptr);
			else
				writel(0xD4000000|(bh->b_size), mptr);
			count -= bh->b_size;
			writel(virt_to_bus(bh->b_data), mptr+4);
			mptr+=8;
			bh = bh->b_reqnext;
		}
	}
	writel(I2O_MESSAGE_SIZE(mptr-msg)>>2 | SGL_OFFSET_8, msg);
	
	if(req->current_nr_sectors > 8)
		printk("Gathered sectors %ld.\n", 
			req->current_nr_sectors);
			
	if(count != 0)
	{
		printk(KERN_ERR "Request count botched by %d.\n", count);
	}

	i2o_post_message(c,m);
	atomic_inc(&queue_depth);

	return 0;
}

/*
 *	Remove a request from the _locked_ request list. We update both the
 *	list chain and if this is the last item the tail pointer. Caller
 *	must hold the lock.
 */
 
static inline void i2ob_unhook_request(struct i2ob_request *ireq)
{
	ireq->next = i2ob_qhead;
	i2ob_qhead = ireq;
}

/*
 *	Request completion handler
 */
 
static void i2ob_end_request(struct request *req)
{
	/*
	 * Loop until all of the buffers that are linked
	 * to this request have been marked updated and
	 * unlocked.
	 */

//	printk("ending request %p: ", req);
	while (end_that_request_first( req, !req->errors, "i2o block" ))
	{
//		printk(" +\n");
	}

	/*
	 * It is now ok to complete the request.
	 */
	
//	printk("finishing ");
	end_that_request_last( req );
//	printk("done\n");
}


/*
 *	OSM reply handler. This gets all the message replies
 */

static void i2o_block_reply(struct i2o_handler *h, struct i2o_controller *c, struct i2o_message *msg)
{
	unsigned long flags;
	struct i2ob_request *ireq;
	u8 st;
	u32 *m = (u32 *)msg;
	u8 unit = (m[2]>>8)&0xF0;	/* low 4 bits are partition */
	struct i2ob_device *dev = &i2ob_dev[(unit&0xF0)];
	
	if(m[0] & (1<<13))
	{
		printk("IOP fail.\n");
		printk("From %d To %d Cmd %d.\n",
			(m[1]>>12)&0xFFF,
			m[1]&0xFFF,
			m[1]>>24);
		printk("Failure Code %d.\n", m[4]>>24);
		if(m[4]&(1<<16))
			printk("Format error.\n");
		if(m[4]&(1<<17))
			printk("Path error.\n");
		if(m[4]&(1<<18))
			printk("Path State.\n");
		if(m[4]&(1<<18))
			printk("Congestion.\n");
		
		m=(u32 *)bus_to_virt(m[7]);
		printk("Failing message is %p.\n", m);
		
		/* We need to up the request failure count here and maybe
		   abort it */
		ireq=&i2ob_queue[m[3]];
		/* Now flush the message by making it a NOP */
		m[0]&=0x00FFFFFF;
		m[0]|=(I2O_CMD_UTIL_NOP)<<24;
		i2o_post_message(c,virt_to_bus(m));
		
	}

	if(msg->function == I2O_CMD_UTIL_EVT_REGISTER)
	{
		spin_lock(&i2ob_evt_lock);
		memcpy(&evt_msg, m, msg->size);
		spin_unlock(&i2ob_evt_lock);
		wake_up_interruptible(&i2ob_evt_wait);
		return;
	}
	if(!dev->i2odev)
	{
		/*
		 * This is HACK, but Intel Integrated RAID allows user
		 * to delete a volume that is claimed, locked, and in use
		 * by the OS. We have to check for a reply from a
		 * non-existent device and flag it as an error or the system
		 * goes kaput...
		 */
		printk(KERN_INFO "I2O Block: Data transfer to deleted device!\n");

		ireq=&i2ob_queue[m[3]];
		ireq->req->errors++;
		printk(KERN_WARNING "I2O Block: Data transfer to deleted device!\n");
		spin_lock_irqsave(&io_request_lock, flags);
		i2ob_unhook_request(ireq);
		i2ob_end_request(ireq->req);
		spin_unlock_irqrestore(&io_request_lock, flags);
		return;
	}
		 
	/*
	 *      Lets see what is cooking. We stuffed the
	 *      request in the context.
	 */

	ireq=&i2ob_queue[m[3]];
	st=m[4]>>24;
	
	if(st!=0)
	{
		char *bsa_errors[] = {
			"Success",
			"Media Error",
			"Failure communicating to device",
			"Device Failure",
			"Device is not ready",
			"Media not present",
			"Media is locked by another user",
			"Media has failed",
			"Failure communicating to device",
			"Device bus failure",
			"Device is locked by another user",
			"Device is write protected",
			"Device has reset",
			"Volume has changed, waiting for acknowledgement"
		};

		printk(KERN_ERR "\n/dev/%s error: %s", dev->i2odev->dev_name, bsa_errors[m[4]&0XFFFF]);

		if(m[4]&0x00FF0000)
			printk(" - DDM attempted %d retries", (m[4]>>16)&0x00FF);
		printk("\n");

		ireq->req->errors++;	
		if (ireq->req->errors < MAX_I2OB_RETRIES)
		{
			u32 retry_msg;
			printk(KERN_ERR "i2ob: attempting retry %d for request %p\n",ireq->req->errors+1,ireq->req);
    				
			/* 
			 * Get a message for this retry.
			 */
	  		retry_msg = i2ob_get(dev);

	  		/* 
			 * If we cannot get a message then
			 * forget the retry and fail the
			 * request.   Note that since this is
			 * being called from the interrupt 
			 * handler, a request has just been 
			 * completed and there will most likely 
			 * be space on the inbound message
			 * fifo so this won't happen often.
			 */
	  		if(retry_msg!=0xFFFFFFFF)
			{
				/*
				 * Decrement the queue depth since
				 * this request has completed and
				 * it will be incremented again when
				 * i2ob_send is called below.
				 */
				atomic_dec(&queue_depth);
				/*
				 * Send the request again.
				 */
				i2ob_send(retry_msg, dev,ireq,i2ob[unit].start_sect, (unit&0xF0));
				/*
				 * Don't fall through.
				 */
				return;
			}
		}		
	}
	else
		ireq->req->errors = 0;
		
	/*
	 *	Dequeue the request. We use irqsave locks as one day we
	 *	may be running polled controllers from a BH...
	 */
	
	spin_lock_irqsave(&io_request_lock, flags);
	i2ob_unhook_request(ireq);
	i2ob_end_request(ireq->req);
	
	/*
	 *	We may be able to do more I/O
	 */
	 
	atomic_dec(&queue_depth);
	i2ob_request();
	spin_unlock_irqrestore(&io_request_lock, flags);
}


/*
 * Event handler.  Needs to be a separate thread b/c we may have
 * to do things like scan a partition table, or query parameters
 * which cannot be done from an interrupt or from a bottom half.
 */
static int i2ob_evt(void *dummy)
{
	 unsigned int evt;
	 unsigned int flags;
	 int unit;
	 int i;
	 struct fs_struct *fs;

	 lock_kernel();

	 exit_files(current);
	 exit_mm(current);
	 current->session = 1;
	 current->pgrp = 1;
	 /* Become as one with the init task */
	 exit_fs(current);
	 fs = init_task.fs;
	 current->fs = fs;
	 atomic_inc(&fs->count);

	 unlock_kernel();

	 strcpy(current->comm, "i2oblock");
	 evt_running = 1;

	 while(1)
	 {
		  interruptible_sleep_on(&i2ob_evt_wait);
		  if(signal_pending(current)) {
			   evt_running = 0;
			   return 0;
		  }

		  /*
		   * Keep another CPU/interrupt from overwriting the
		   * message while we're reading it
		   *
		   * We stuffed the unit in the TxContext and grab the event mask
		   * None of the BSA we care about events have EventData
		   */
		  spin_lock_irqsave(&i2ob_evt_lock, flags);
		  unit = evt_msg[3];
		  evt = evt_msg[4];
		  spin_unlock_irqrestore(&i2ob_evt_lock, flags);

		  switch(evt)
		  {
			   /*
			    * New volume loaded on same TID, so we just re-install.			    
			    * The TID/controller don't change as it is the same
			    * I2O device.  It's just new media that we have to
			    * rescan.
			    */
			   case I2O_EVT_IND_BSA_VOLUME_LOAD:
			   {
				    i2ob_install_device(i2ob_dev[unit].i2odev->controller,
					     i2ob_dev[unit].i2odev, unit);
				    break;
			   }

			   /*
			    * No media, so set all parameters to 0 and set the media
			    * change flag. The I2O device is still valid, just doesn't
			    * have media, so we don't want to clear the controller or
			    * device pointer.
			    */
			   case I2O_EVT_IND_BSA_VOLUME_UNLOAD:
			   {
				    for(i = unit; i <= unit+15; i++)
				    {
					     i2ob_sizes[i] = 0;
					     i2ob_hardsizes[i] = 0;
					     i2ob_max_sectors[i] = 0;
					     i2ob[i].nr_sects = 0;
					     i2ob_gendisk.part[i].nr_sects = 0;
				    }
				    i2ob_media_change_flag[unit] = 1;
				    break;
			   }

			   case I2O_EVT_IND_BSA_VOLUME_UNLOAD_REQ:
				    printk(KERN_WARNING "%s: Attempt to eject locked media\n",
					     i2ob_dev[unit].i2odev->dev_name);
				    break;

			   /*
			    * The capacity has changed and we are going to be
			    * updating the max_sectors and other information
			    * about this disk.  We try a revalidate first. If
			    * the block device is in use, we don't want to
			    * do that as there may be I/Os bound for the disk
			    * at the moment.  In that case we read the size
			    * from the device and update the information ourselves
			    * and the user can later force a partition table
			    * update through an ioctl.
			    */
			   case I2O_EVT_IND_BSA_CAPACITY_CHANGE:
			   {
				    u64 size;

				    if(do_i2ob_revalidate(MKDEV(MAJOR_NR, unit),0) != -EBUSY)
					     continue;

				    if(i2ob_query_device(&i2ob_dev[unit], 0x0004, 0, &size, 8) !=0 )
					     i2ob_query_device(&i2ob_dev[unit], 0x0000, 4, &size, 8);

				    spin_lock_irqsave(&io_request_lock, flags);
				    i2ob_sizes[unit] = (int)(size>>10);
				    i2ob_gendisk.part[unit].nr_sects = size>>9;
				    i2ob[unit].nr_sects = (int)(size>>9);
				    spin_unlock_irqrestore(&io_request_lock, flags); 
				    break;
			   }

			   /*
			    * An event we didn't ask for.  Call the card manufacturer
			    * and tell them to fix their firmware :)
			    */
			   default:
				    printk(KERN_INFO "%s: Received event we didn't register for\n"
					     KERN_INFO "   Call I2O card manufacturer\n",
					     i2ob_dev[unit].i2odev->dev_name);
				    break;
		  }
	 };

	 return 0;
}


static struct i2o_handler i2o_block_handler =
{
	i2o_block_reply,
	i2ob_new_device,
	i2ob_del_device,
	i2ob_reboot_event,
	"I2O Block OSM",
	0,
	I2O_CLASS_RANDOM_BLOCK_STORAGE
};

/*
 * The timer handler will attempt to restart requests 
 * that are queued to the driver.  This handler
 * currently only gets called if the controller
 * had no more room in its inbound fifo.  
 */

static void i2ob_timer_handler(unsigned long dummy)
{
	unsigned long flags;

	/*
	 * We cannot touch the request queue or the timer
	  * flag without holding the io_request_lock.
	 */
	spin_lock_irqsave(&io_request_lock,flags);

	/* 
	 * Clear the timer started flag so that 
	 * the timer can be queued again.
	 */
	i2ob_timer_started = 0;

	/* 
	 * Restart any requests.
	 */
	i2ob_request();

	/* 
	 * Free the lock.
	 */
	spin_unlock_irqrestore(&io_request_lock,flags);
}

/*
 *	The I2O block driver is listed as one of those that pulls the
 *	front entry off the queue before processing it. This is important
 *	to remember here. If we drop the io lock then CURRENT will change
 *	on us. We must unlink CURRENT in this routine before we return, if
 *	we use it.
 */

static void i2ob_request(void)
{
	unsigned long flags;
	struct request *req;
	struct i2ob_request *ireq;
	int unit;
	struct i2ob_device *dev;
	u32 m;

	while (CURRENT) {
		/*
		 *	On an IRQ completion if there is an inactive
		 *	request on the queue head it means it isnt yet
		 *	ready to dispatch.
		 */
		if(CURRENT->rq_status == RQ_INACTIVE)
			return;
			
		/*
		 *	Queue depths probably belong with some kind of
		 *	generic IOP commit control. Certainly its not right
		 *	its global!
		 */
		if(atomic_read(&queue_depth)>=MAX_I2OB_DEPTH)
			break;

		req = CURRENT;
		unit = MINOR(req->rq_dev);
		dev = &i2ob_dev[(unit&0xF0)];

		/*
		 * Check to see if the request is for a deleted/non-existent
		 * device. If so return.
		 */
		if (dev->i2odev == NULL)
		{
			printk("I2O: ERROR I/O Request to a non existent device !\n");
			req->errors = 1;
			CURRENT = CURRENT->next;
			req->sem = NULL;	
			i2ob_end_request(req);	
			continue;
		}

		/* Get a message */
		m = i2ob_get(dev);

		if(m==0xFFFFFFFF)
		{
			/* 
			 * See if the timer has already been queued.
			 */
			if (!i2ob_timer_started)
			{
				printk(KERN_ERR "i2ob: starting timer\n");

				/*
				 * Set the timer_started flag to insure
				 * that the timer is only queued once.
				 * Queing it more than once will corrupt
				 * the timer queue.
				 */
				i2ob_timer_started = 1;

				/* 
				 * Set up the timer to expire in
				 * 500ms.
				 */
				i2ob_timer.expires = jiffies + (HZ >> 1);

				/*
				 * Start it.
				 */
				 
				add_timer(&i2ob_timer);
			}
		}
		req->errors = 0;
		CURRENT = CURRENT->next;
		req->sem = NULL;
		
		ireq = i2ob_qhead;
		i2ob_qhead = ireq->next;
		ireq->req = req;

		i2ob_send(m, dev, ireq, i2ob[unit].start_sect, (unit&0xF0));
	}
}

/*
 *	SCSI-CAM for ioctl geometry mapping
 *	Duplicated with SCSI - this should be moved into somewhere common
 *	perhaps genhd ?
 */
 
static void i2o_block_biosparam(
	unsigned long capacity,
	unsigned short *cyls,
	unsigned char *hds,
	unsigned char *secs) 
{ 
	unsigned long heads, sectors, cylinders, temp; 

	cylinders = 1024L;			/* Set number of cylinders to max */ 
	sectors = 62L;      			/* Maximize sectors per track */ 

	temp = cylinders * sectors;		/* Compute divisor for heads */ 
	heads = capacity / temp;		/* Compute value for number of heads */
	if (capacity % temp) {			/* If no remainder, done! */ 
    		heads++;		  	/* Else, increment number of heads */ 
    		temp = cylinders * heads;	/* Compute divisor for sectors */ 
    		sectors = capacity / temp;	/* Compute value for sectors per
							track */ 
	    	if (capacity % temp) {		/* If no remainder, done! */ 
			sectors++;		    /* Else, increment number of sectors */ 
	      		temp = heads * sectors;	/* Compute divisor for cylinders */
	      		cylinders = capacity / temp;/* Compute number of cylinders */ 
		} 
	} 
	/* if something went wrong, then apparently we have to return
	   a geometry with more than 1024 cylinders */
	if (cylinders == 0 || heads > 255 || sectors > 63 || cylinders >1023) 
	{
		unsigned long temp_cyl;
		
		heads = 64;
		sectors = 32;
		temp_cyl = capacity / (heads * sectors);
		if (temp_cyl > 1024) 
		{
			heads = 255;
			sectors = 63;
		}
		cylinders = capacity / (heads * sectors);
	}
	*cyls = (unsigned int) cylinders;	/* Stuff return values */ 
	*secs = (unsigned int) sectors; 
	*hds  = (unsigned int) heads; 
} 

/*
 *	Rescan the partition tables
 */
 
static int do_i2ob_revalidate(kdev_t dev, int maxu)
{
	int minor=MINOR(dev);
	int i;
	
	minor&=0xF0;
	
	i2ob_dev[minor].refcnt++;
	if(i2ob_dev[minor].refcnt>maxu+1)
	{
		i2ob_dev[minor].refcnt--;
		return -EBUSY;
	}
	
	for( i = 15; i>=0 ; i--)
	{
		int m = minor+i;
		kdev_t d = MKDEV(MAJOR_NR, m);
		struct super_block *sb = get_super(d);
		
		sync_dev(d);
		if(sb)
			invalidate_inodes(sb);
		invalidate_buffers(d);
		i2ob_gendisk.part[m].start_sect = 0;
		i2ob_gendisk.part[m].nr_sects = 0;
	}

	/*
	 *	Do a physical check and then reconfigure
	 */
	 
	i2ob_install_device(i2ob_dev[minor].controller, i2ob_dev[minor].i2odev,
		minor);
	i2ob_dev[minor].refcnt--;
	return 0;
}

/*
 *	Issue device specific ioctl calls.
 */

static int i2ob_ioctl(struct inode *inode, struct file *file,
		     unsigned int cmd, unsigned long arg)
{
	struct i2ob_device *dev;
	int minor;

	/* Anyone capable of this syscall can do *real bad* things */

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	if (!inode)
		return -EINVAL;
	minor = MINOR(inode->i_rdev);
	if (minor >= (MAX_I2OB<<4))
		return -ENODEV;

	dev = &i2ob_dev[minor];
	switch (cmd) {
		case BLKRASET:
			if(!capable(CAP_SYS_ADMIN))  return -EACCES;
			if(arg > 0xff) return -EINVAL;
			read_ahead[MAJOR(inode->i_rdev)] = arg;
			return 0;

		case BLKRAGET:
			if (!arg)  return -EINVAL;
			return put_user(read_ahead[MAJOR(inode->i_rdev)],
					(long *) arg); 
		case BLKGETSIZE:
			return put_user(i2ob[minor].nr_sects, (long *) arg);

		case BLKFLSBUF:
			if(!capable(CAP_SYS_ADMIN))  return -EACCES;
			fsync_dev(inode->i_rdev);
			invalidate_buffers(inode->i_rdev);
			return 0;
			
		case HDIO_GETGEO:
		{
			struct hd_geometry g;
			int u=minor&0xF0;
			i2o_block_biosparam(i2ob_sizes[u]<<1, 
				&g.cylinders, &g.heads, &g.sectors);
			g.start = i2ob[minor].start_sect;
			return copy_to_user((void *)arg,&g, sizeof(g))?-EFAULT:0;
		}
		
		RO_IOCTLS(inode->i_rdev, arg);
	
		case BLKRRPART:
			if(!capable(CAP_SYS_ADMIN))
				return -EACCES;
			return do_i2ob_revalidate(inode->i_rdev,1);
			
			
		default:
			return -EINVAL;
	}
}

/*
 *	Close the block device down
 */
 
static int i2ob_release(struct inode *inode, struct file *file)
{
	struct i2ob_device *dev;
	int minor;

	minor = MINOR(inode->i_rdev);
	if (minor >= (MAX_I2OB<<4))
		return -ENODEV;
	dev = &i2ob_dev[(minor&0xF0)];

	/*
	 * This is to deal with the case of an application
	 * opening a device and then the device dissapears while
	 * it's in use, and then the application tries to release
	 * it.  ex: Unmounting a deleted RAID volume at reboot.
	 * If we send messages, it will just cause FAILs since
	 * the TID no longer exists.
	 */
	if(!dev->i2odev)
		{
		printk(KERN_INFO "I2O : ERROR No such Device\n");
		return 0;
		}

	/* Sync the device so we don't get errors */
	fsync_dev(inode->i_rdev);

	if (dev->refcnt <= 0)
		printk(KERN_ALERT "i2ob_release: refcount(%d) <= 0\n", dev->refcnt);
	dev->refcnt--;
	if(dev->refcnt==0)
	{
		/*
		 *	Flush the onboard cache on unmount
		 */
		u32 msg[5];
		int *query_done = &dev->done_flag;

		fsync_dev(inode->i_rdev);

		msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
		msg[1] = I2O_CMD_BLOCK_CFLUSH<<24|HOST_TID<<12|dev->tid;
		msg[2] = i2ob_context|0x40000000;
		msg[3] = (u32)query_done;
		msg[4] = 60<<16;
		i2o_post_wait(dev->controller, msg, 20, 2);
		/*
		 *	Unlock the media
		 */
		msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
		msg[1] = I2O_CMD_BLOCK_MUNLOCK<<24|HOST_TID<<12|dev->tid;
		msg[2] = i2ob_context|0x40000000;
		msg[3] = (u32)query_done;
		msg[4] = -1;
		i2o_post_wait(dev->controller, msg, 20, 2);
	
		/*
 		 * Now unclaim the device.
		 */
		if (i2o_release_device(dev->i2odev, &i2o_block_handler)<0)
			printk(KERN_ERR "i2ob_release: controller rejected unclaim.\n");

	}
	MOD_DEC_USE_COUNT;
	return 0;
}

/*
 *	Open the block device.
 */
 
static int i2ob_open(struct inode *inode, struct file *file)
{
	int minor;
	struct i2ob_device *dev;
	
	if (!inode)
		return -EINVAL;
	minor = MINOR(inode->i_rdev);
	if (minor >= MAX_I2OB<<4)
		return -ENODEV;
	dev=&i2ob_dev[(minor&0xF0)];
	if(dev->i2odev == NULL)
		return -ENODEV;
		
	if(dev->refcnt++==0)
	{ 
		u32 msg[6];
		int *query_done;
		
		
		if(i2o_claim_device(dev->i2odev, &i2o_block_handler)<0)
		{
			dev->refcnt--;
			return -EBUSY;
		}
		
		query_done = &dev->done_flag;
		/*
		 *	Mount the media if needed. Note that we don't use
		 *	the lock bit. Since we have to issue a lock if it
		 *	refuses a mount (quite possible) then we might as
		 *	well just send two messages out.
		 */
		msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;		
		msg[1] = I2O_CMD_BLOCK_MMOUNT<<24|HOST_TID<<12|dev->tid;
		msg[2] = i2ob_context|0x40000000;
		msg[3] = (u32)query_done;
		msg[4] = -1;
		msg[5] = 0;
		i2o_post_wait(dev->controller, msg, 24, 2);
		/*
		 *	Lock the media
		 */
		msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
		msg[1] = I2O_CMD_BLOCK_MLOCK<<24|HOST_TID<<12|dev->tid;
		msg[2] = i2ob_context|0x40000000;
		msg[3] = (u32)query_done;
		msg[4] = -1;
		i2o_post_wait(dev->controller, msg, 20, 2);
	}		
	MOD_INC_USE_COUNT;
	return 0;
}

/*
 *	Issue a device query
 */
 
static int i2ob_query_device(struct i2ob_device *dev, int table, 
	int field, void *buf, int buflen)
{
	return i2o_query_scalar(dev->controller, dev->tid,
		table, field, buf, buflen);
}


/*
 *	Install the I2O block device we found.
 */
 
static int i2ob_install_device(struct i2o_controller *c, struct i2o_device *d, int unit)
{
	u64 size;
	u32 blocksize;
	u32 limit;
	u8 type;
	u32 flags, status;
	struct i2ob_device *dev=&i2ob_dev[unit];
	int i;

	 /*
	  * For logging purposes...
	  */
	 printk(KERN_INFO "i2ob: Installing tid %d device at unit %d\n",
			   d->lct_data.tid, unit);

	/*
	 *	Ask for the current media data. If that isn't supported
	 *	then we ask for the device capacity data
	 */
	if(i2ob_query_device(dev, 0x0004, 1, &blocksize, 4) != 0
	  || i2ob_query_device(dev, 0x0004, 0, &size, 8) !=0 )
	{
		i2ob_query_device(dev, 0x0000, 3, &blocksize, 4);
		i2ob_query_device(dev, 0x0000, 4, &size, 8);
	}
	
	i2ob_query_device(dev, 0x0000, 5, &flags, 4);
	i2ob_query_device(dev, 0x0000, 6, &status, 4);
	i2ob_sizes[unit] = (int)(size>>10);
	i2ob_hardsizes[unit] = blocksize;
	i2ob_gendisk.part[unit].nr_sects = size>>9;
	i2ob[unit].nr_sects = (int)(size>>9);

	 /* Set limit based on inbound frame size */
	 limit = (d->controller->status_block->inbound_frame_size - 8)/2;
	 limit = limit<<9;

	 /*
	  * Max number of Scatter-Gather Elements
	  */
	 i2ob_dev[unit].max_segments =
		  (d->controller->status_block->inbound_frame_size - 8)/2;

	 printk(KERN_INFO "Max Segments set to %d\n",
				    i2ob_dev[unit].max_segments);
	 printk(KERN_INFO "Byte limit is %d.\n", limit);

	 for(i=unit;i<=unit+15;i++)
	 {
		  i2ob_max_sectors[i]=MAX_SECTORS;
		  i2ob_dev[i].max_segments =
			   (d->controller->status_block->inbound_frame_size - 8)/2;	 }


	i2ob_query_device(dev, 0x0000, 0, &type, 1);
	
	sprintf(d->dev_name, "%s%c", i2ob_gendisk.major_name, 'a' + (unit>>4));

	printk(KERN_INFO "%s: ", d->dev_name);

	if(status&(1<<10))
		printk("(RAID) ");
	switch(type)
	{
		case 0: printk("Disk Storage");break;
		case 4: printk("WORM");break;
		case 5: printk("CD-ROM");break;
		case 7:	printk("Optical device");break;
		default:
			printk("Type %d", type);
	}
	if(((flags & (1<<3)) && !(status & (1<<3))) ||
	   ((flags & (1<<4)) && !(status & (1<<4))))
	{
		printk(KERN_INFO " Not loaded.\n");
		return 1;
	}
	printk("- %dMb, %d byte sectors",
		(int)(size>>20), blocksize);
	if(status&(1<<0))
	{
		u32 cachesize;
		i2ob_query_device(dev, 0x0003, 0, &cachesize, 4);
		cachesize>>=10;
		if(cachesize>4095)
			printk(", %dMb cache", cachesize>>10);
		else
			printk(", %dKb cache", cachesize);
	}
	printk(".\n");
	printk(KERN_INFO "%s: Maximum sectors/read set to %d.\n", 
		d->dev_name, i2ob_max_sectors[unit]);

	resetup_one_dev(&i2ob_gendisk, unit>>4);

	 /*
	  * Register for the events we're interested in and that the
	  * device actually supports.
	  */
	 i2o_event_register(c, d->lct_data.tid, i2ob_context, unit,
		  (I2OB_EVENT_MASK & d->lct_data.event_capabilities));

	return 0;
}

static int i2ob_scan(int bios)
{
	int i;
	int warned = 0;
	struct i2o_device *d, *b=NULL;
	struct i2o_controller *c;
	struct i2ob_device *dev;
		
	for(i=0; i< MAX_I2O_CONTROLLERS; i++)
	{
		c=i2o_find_controller(i);

		if(c==NULL)
			continue;

		/* 
		 * 	The device list connected to the I2O Controller is doubly linked
		 *	Here we traverse the end of the list , and start claiming devices
		 *	from that end. This assures that within an I2O controller atleast
		 *	the newly created volumes get claimed after the older ones, thus
		 *	mapping to same major/minor (and hence device file name) after 
		 *	every reboot.
		 *	The exception being: 
		 *	1. If there was a TID reuse.
		 *	2. There was more than one I2O controller. 
		 */

		if(!bios)
		{
			for (d=c->devices;d!=NULL;d=d->next)
				if(d->next == NULL)
					b = d;
		}
		else
			b = c->devices;
		
		while(b != NULL)
		{
			d=b;
			if(bios)
				b = b->next;
			else
				b = b->prev;
			
			if(d->lct_data.class_id!=I2O_CLASS_RANDOM_BLOCK_STORAGE)
				continue;
			if(d->lct_data.user_tid != 0xFFF)
				continue;
			if(bios)
			{
				if(d->lct_data.bios_info != 0x80)
					continue;
				printk(KERN_INFO "Claiming as Boot device: Controller %d, TID %d\n", c->unit, d->lct_data.tid);
			}
			else
			{
				if(d->lct_data.bios_info == 0x80)
					continue;	/* Already claimed on pass 1 */
			}
			if(i2o_claim_device(d, &i2o_block_handler))
			{
				printk(KERN_WARNING "i2o_block: Controller %d, TID %d\n", c->unit, d->lct_data.tid);
				printk(KERN_WARNING "\t%sevice refused claim! Skipping installation\n",
					bios?"Boot d":"D");
				continue;
			}
			if(scan_unit<MAX_I2OB<<4)
			{
				/*
				 * Get the device and fill in the
				 * Tid and controller.
				 */
				dev=&i2ob_dev[scan_unit];
				dev->i2odev = d;
				dev->controller = c;
				dev->unit = c->unit;
				dev->tid = d->lct_data.tid;
				if(i2ob_install_device(c,d,scan_unit))
					printk(KERN_WARNING "Could not install I2O block device\n");
				else
				{
					scan_unit+=16;
					i2ob_dev_count++;
					/* We want to know when device goes away */
					i2o_device_notify_on(d, &i2o_block_handler);
				}
			}
			else
			{
				if(!warned++)
					printk(KERN_WARNING "i2o_block: too many device, registering only %d.\n", scan_unit>>4);
			}
			i2o_release_device(d, &i2o_block_handler);
		}
		i2o_unlock_controller(c);
	}
	return 0;
}

static void i2ob_probe(void)
{
	/* 
	 *	Some overhead/redundancy involved here, while trying to
	 *	claim the first boot volume encountered as /dev/i2o/hda
	 *	everytime. All the i2o_controllers are searched and the
	 *	first i2o block device marked as bootable is claimed
	 *	If an I2O block device was booted off , the bios sets
	 *	its bios_info field to 0x80, this what we search for.
 	 *	Assuming that the bootable volume is /dev/i2o/hda
	 *	everytime will prevent any kernel panic while mounting
	 *	root partition
	 */ 

	printk(KERN_INFO "i2o_block: Checking for Boot device...\n");
	i2ob_scan(1);
	
	/*
	 *	Now the remainder.
	 */
	printk(KERN_INFO "i2o_block: Checking for I2O Block devices...\n"); 
	i2ob_scan(0);
}

/*
 * New device notification handler.  Called whenever a new
 * I2O block storage device is added to the system.
 *
 * Should we spin lock around this to keep multiple devs from
 * getting updated at the same time?
 *
 */

void i2ob_new_device(struct i2o_controller *c, struct i2o_device *d)
{
	 struct i2ob_device *dev;
	 int unit = 0;

	 printk(KERN_INFO "i2o_block: New device detected\n");
	 printk(KERN_INFO "   Controller %d Tid %d\n",c->unit, d->lct_data.tid);

	 /* Check for available space */
	 if(i2ob_dev_count>=MAX_I2OB<<4)
	 {
		  printk(KERN_ERR "i2o_block: No more devices allowed!\n");
		  return;
	 }
	 for(unit = 0; unit < (MAX_I2OB<<4); unit += 16)
	 {
		  if(!i2ob_dev[unit].i2odev)
			   break;
	 }

	 if(i2o_claim_device(d, &i2o_block_handler))
	 {
		  printk(KERN_INFO
			   "i2o_block: Unable to claim device. Installation aborted\n");
		  return;
	 }

	 dev = &i2ob_dev[unit];
	 dev->i2odev = d;
	 dev->controller = c;
	 dev->tid = d->lct_data.tid;

	 if(i2ob_install_device(c,d,unit))
		  printk(KERN_ERR "i2o_block: Could not install new device\n");
	 else
	 {
		  i2ob_dev_count++;
		  i2o_device_notify_on(d, &i2o_block_handler);
	 }

	 i2o_release_device(d, &i2o_block_handler);

	 return;
}

/*
 * Deleted device notification handler.  Called when a device we
 * are talking to has been deleted by the user or some other
 * mysterious fource outside the kernel.
 */
void i2ob_del_device(struct i2o_controller *c, struct i2o_device *d)
{
	 int unit = 0;
	 int i = 0;
	 int flags;

	 spin_lock_irqsave(&io_request_lock, flags);

	 /*
	  * Need to do this...we somtimes get two events from the IRTOS
	  * in a row and that causes lots of problems.
	  */

	 i2o_device_notify_off(d, &i2o_block_handler);

	 printk(KERN_INFO "I2O Block Device Deleted\n");

	 for(unit = 0; unit < MAX_I2OB<<4; unit += 16)
	 {
		  if(i2ob_dev[unit].i2odev == d)
		  {
			   printk(KERN_INFO "  /dev/%s: Controller %d Tid %d\n",
				    d->dev_name, c->unit, d->lct_data.tid);
			   break;
		  }
	 }
	 if(unit >= MAX_I2OB<<4)
	 {
		  printk(KERN_ERR "i2ob_del_device called, but not in dev table!\n");
		  return;
	 }

	 for(i = unit; i <= unit+15; i++)
	 {
		  i2ob_dev[i].i2odev = NULL;
		  i2ob_sizes[i] = 0;
		  i2ob_hardsizes[i] = 0;
		  i2ob_max_sectors[i] = 0;
		  i2ob[i].nr_sects = 0;
		  i2ob_gendisk.part[i].nr_sects = 0;
	 }
	 spin_unlock_irqrestore(&io_request_lock, flags);

	 /*
	  * Sync the device...this will force all outstanding I/Os
	  * to attempt to complete, thus causing error messages.
	  * We have to do this as the user could immediatelly create
	  * a new volume that gets assigned the same minor number.
	  * If there are still outstanding writes to the device,
	  * that could cause data corruption on the new volume!
	  *
	  * The truth is that deleting a volume that you are currently
	  * accessing will do _bad things_ to your system.  This
	  * handler will keep it from crashing, but must probably
	  * you'll have to do a 'reboot' to get the system running
	  * properly.  Deleting disks you are using is dumb.
	  * Umount them first and all will be good!
	  *
	  * It's not this driver's job to protect the system from
	  * dumb user mistakes :)
	  */
	 if(i2ob_dev[unit].refcnt)
		  fsync_dev(MKDEV(MAJOR_NR,unit));

	 /*
	  * Decrease usage count for module
	  */
	 while(i2ob_dev[unit].refcnt--)
		  MOD_DEC_USE_COUNT;

	 i2ob_dev[unit].refcnt = 0;

	 i2ob_dev[i].tid = 0;

	 /*
	  * Do we need this?
	  * The media didn't really change...the device is just gone
	  */
	 i2ob_media_change_flag[unit] = 1;

	 i2ob_dev_count--;

	 return;
}



/*
 *	Have we seen a media change ?
 */
 
static int i2ob_media_change(kdev_t dev)
{
	int i=MINOR(dev);
	i>>=4;
	if(i2ob_media_change_flag[i])
	{
		i2ob_media_change_flag[i]=0;
		return 1;
	}
	return 0;
}

static int i2ob_revalidate(kdev_t dev)
{
	return do_i2ob_revalidate(dev, 0);
}

static void i2ob_reboot_event(void)
{
	int i;
	
	for(i=0;i<MAX_I2OB;i++)
	{
		struct i2ob_device *dev=&i2ob_dev[(i<<4)];
		
		if(dev->refcnt!=0)
		{
			/*
			 *	Flush the onboard cache on power down
			 *	also unlock the media
			 */
			u32 msg[5];
			int *query_done = &dev->done_flag;
			msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
			msg[1] = I2O_CMD_BLOCK_CFLUSH<<24|HOST_TID<<12|dev->tid;
			msg[2] = i2ob_context|0x40000000;
			msg[3] = (u32)query_done;
			msg[4] = 60<<16;
			i2o_post_wait(dev->controller, msg, 20, 2);
			/*
			 *	Unlock the media
			 */
			msg[0] = FIVE_WORD_MSG_SIZE|SGL_OFFSET_0;
			msg[1] = I2O_CMD_BLOCK_MUNLOCK<<24|HOST_TID<<12|dev->tid;
			msg[2] = i2ob_context|0x40000000;
			msg[3] = (u32)query_done;
			msg[4] = -1;
			i2o_post_wait(dev->controller, msg, 20, 2);
		}
	}	
}

static struct file_operations i2ob_fops =
{
	NULL,			/* lseek - default */
	block_read,		/* read - general block-dev read */
	block_write,		/* write - general block-dev write */
	NULL,			/* readdir - bad */
	NULL,			/* select */
	i2ob_ioctl,		/* ioctl */
	NULL,			/* mmap */
	i2ob_open,		/* open */
	NULL,			/* flush */
	i2ob_release,		/* release */
	NULL,			/* fsync */
	NULL,			/* fasync */
	i2ob_media_change,	/* Media Change */
	i2ob_revalidate,	/* Revalidate */
	NULL			/* File locks */
};

static void i2ob_geninit(struct gendisk *gd)
{
}

	
static struct gendisk i2ob_gendisk = 
{
	MAJOR_NR,
	"i2ohd",
	4,
	1<<4,
	MAX_I2OB,
	i2ob_geninit,
	i2ob,
	i2ob_sizes,
	0,
	NULL,
	NULL
};

/*
 * And here should be modules and kernel interface 
 *  (Just smiley confuses emacs :-)
 */

#ifdef MODULE
#define i2o_block_init init_module
#endif

int i2o_block_init(void)
{
	int i;

	printk(KERN_INFO "I2O Block Storage OSM v0.9. (C) 1999 Red Hat Software.\n");
	
	/*
	 *	Register the block device interfaces
	 */

	if (register_blkdev(MAJOR_NR, "i2o_block", &i2ob_fops)) {
		printk(KERN_ERR "Unable to get major number %d for i2o_block\n",
			MAJOR_NR);
		return -EIO;
	}
#ifdef MODULE
	printk(KERN_INFO "i2o_block: registered device at major %d\n", MAJOR_NR);
#endif

	/*
	 *	Now fill in the boiler plate
	 */
	 
	blksize_size[MAJOR_NR] = i2ob_blksizes;
	hardsect_size[MAJOR_NR] = i2ob_hardsizes;
	blk_size[MAJOR_NR] = i2ob_sizes;
	max_sectors[MAJOR_NR] = i2ob_max_sectors;
	blk_dev[MAJOR_NR].request_fn = i2ob_request;	

	for (i = 0; i < MAX_I2OB << 4; i++) {
		i2ob_dev[i].refcnt = 0;
		i2ob_dev[i].flags = 0;
		i2ob_dev[i].controller = NULL;
		i2ob_dev[i].i2odev = NULL;
		i2ob_dev[i].tid = 0;
		i2ob_dev[i].head = NULL;
		i2ob_dev[i].tail = NULL;
		i2ob_blksizes[i] = 1024;
		i2ob_max_sectors[i] = 2;
	}
	
	/*
	 *	Set up the queue
	 */
	
	for(i = 0; i< MAX_I2OB_DEPTH; i++)
	{
		i2ob_queue[i].next = &i2ob_queue[i+1];
		i2ob_queue[i].num = i;
	}
	
	/* Queue is MAX_I2OB + 1... */
	i2ob_queue[i].next = NULL;
	i2ob_qhead = &i2ob_queue[0];
	
	/*
	 *	Timers
	 */
	 
	init_timer(&i2ob_timer);
	i2ob_timer.function = i2ob_timer_handler;
	i2ob_timer.data = 0;
	
	/*
	 *	Register the OSM handler as we will need this to probe for
	 *	drives, geometry and other goodies.
	 */

	if(i2o_install_handler(&i2o_block_handler)<0)
	{
		unregister_blkdev(MAJOR_NR, "i2o_block");
		printk(KERN_ERR "i2o_block: unable to register OSM.\n");
		return -EINVAL;
	}
	i2ob_context = i2o_block_handler.context;	 

	 /*
	  * Initialize event handling thread
	  */
	 sema_init(&i2ob_evt_sem, 0);
	 evt_pid = kernel_thread(i2ob_evt, NULL, CLONE_SIGHAND);
	 if(evt_pid < 0)
	 {
		  printk(KERN_ERR
			   "i2o_block: Could not initialize event thread.  Aborting\n");
		  i2o_remove_handler(&i2o_block_handler);
		  return 0;
	 }


	/*
	 *	Finally see what is actually plugged in to our controllers
	 */
	i2ob_probe();

	return 0;
}

#ifdef MODULE

EXPORT_NO_SYMBOLS;
MODULE_AUTHOR("Red Hat Software");
MODULE_DESCRIPTION("I2O Block Device OSM");

void cleanup_module(void)
{
	struct gendisk **gdp;
	int i;
	
	 /*
	  * Unregister for updates from any devices..otherwise we still
	  * get them and the core jumps to random memory :O
	  */
	 if(i2ob_dev_count) {
		  struct i2o_device *d;
		  for(i = 0; i < MAX_I2OB; i++)
		  if((d=i2ob_dev[i<<4].i2odev)) {
			   i2o_device_notify_off(d, &i2o_block_handler);
			   i2o_event_register(d->controller, d->lct_data.tid,
				    i2ob_context, i<<4, 0);
		  }
	 }

	/*
	 *	Flush the OSM
	 */

	i2o_remove_handler(&i2o_block_handler);
		 
	/*
	 *	Return the block device
	 */
	if (unregister_blkdev(MAJOR_NR, "i2o_block") != 0)
		printk("i2o_block: cleanup_module failed\n");

	if(evt_running) {
		  i = kill_proc(evt_pid, SIGTERM, 1);
		  if(!i) {
			   int count = 5 * 100;
			   while(evt_running && --count) {
				    current->state = TASK_INTERRUPTIBLE;
				    schedule_timeout(1);
			   }

			   if(!count)
				    printk(KERN_ERR "Giving up on i2oblock thread...\n");
		  }

}

	/*
	 *	Why isnt register/unregister gendisk in the kernel ???
	 */

	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
		if (*gdp == &i2ob_gendisk)
			break;

}
#endif
